Apparatus for and process of making reinforced tubing



A. J. BERG APPARATUS FOR AND PROCESS OF MAKING hEmFoRcED TUBING March28, 1939.

Fild Feb. 14, 1936 IN V EN TOR. ALFRED J. BERG A TTORNEYS.

' Patented M 28, 1939 umrso STATES Arransrus roa Ann rnocnss or mamaaamrolwen TUBING a Alfred r. erml'ol'tsmouth, 191. n.

Application February 14,.19sa'seue1 No. 63,899

5 can". (01. 15.2-04.5)

(Granted under the act of Mai-en 3, amended April 30, 1928; 370 0. G.

My invention relates to a reinforced tube or body and a method ofproducing the same.

The objectsof my invention are to make a very light pipe or tube ofgreat strength as well as 5 afford a pipe or tube of attractiveappearance which shall be uniformly smooth and free from irregularitiesin which may accumulate dirt, dust and other foreign matter.

A further object of my invention is to provide reinforced pipe or tubevery light in weight and of great strength in which the reinforcementprojects at intervals about the tube and prevents 'undue thinning of thewall of the tube by wear and in which the suriacm of the reinforcementare-uniformly smooth and free from irregularities which may invite theformation oi deposits I of dust or other foreign matte A- further objectof my invention is to provide a new anduseful process by whichthereinforced 20'rpipe or tube may be made commercially, and whichprocess may be performed by hand.

In the accompanying drawing illustrating my invention, Fig. 1 is a topplan view of a portion of the reinforcing band helicallyprefonned aboutthe tube or body.

Figure 2 is a perspective view of the subject of .Fig. 1, with jointsbroken away and disclosing the securing feet formed alternately atintervals upon the inner edge of the reinforcing band:

Fig. 3 is a central longitudinal sectional plan view of a portion of apipe or tube;

my helical reinforcing band;

'Figs. 4'and 5 areviews similar to-Fig. 3 but showing diiferentsecurements of the feet:

Fig, 6 is an end view with section and other parts broken away for clillustrating an apparatus for'making the heat or cold exchanging elementin accordance with my invention;

Figfi with portions of the tube and its rilnbeing in section;

In the in which-like haracters of' reference indicate the same parts, II is the tube orpther body which may be hollow and which is to to bereinforced and whose wall I ently prefer to haverelatively thin' for theCharacter of serviceand pressure to which the sarheisto' be subjected;For the reinforcing band-'or bands Iprefer-to employ a metallicstrlp' II, preferably 'i' of very thin metal bent about the tube.

provided with the tube in cross-- Fig.7isaside elevationviewofpartsshownin 1883, as 757) This bending may be about the tube. or the onecontinuous strip II wide thin strip of metal, I I signedly permitted toform hthe tube or arched surface must be maintained under .verysubstantial longitudinal stress of, a magnitude sufilcient to stretchthe metal during the period that, and at-the live 5.

points where, molecular action of the metal of the strip is taking placein the edgewise bending of such strip about the tube or arched surface.This longitudinal stress upon the strip ll occas sio'ns a substantiallateral ;th'rust upon the tube or arched surface of the body ll whilethe same produc on. Such lateral stress applied to the 10 tube or bodyII at points progressively varying throughout its length, during therotation of the tube or body ll, tends to laterally deflect the tube orbody I! at a rapid rate and exerts a 15 metal of such tube or body II. Asteady rest has been employed in the prior practice to reduce as far aspracticable the amplitude of such vibrations of the tube or body Itwhile being helically finned or ribbed, but such steady rests 20 mar andwear the surface of the tube or body ill due to the magnitude of saidlateral stress upon the rotating pipe or body iii.

In my present invention, the very wide thin strip of metal II islooselylead into contact with 25 tube or body II, with one lateral edgeof an end of strip Ii in contact with and secured by solder or otherwiseto the outer surface of the tube or body III. This initial-securement ofthe strip II to tube or body II occupies but a small area. An

30 area at both sides of the outer portion of said strip II is closelyconfined by surfaces 28 which hold the strip II in its upright positionas the same is to be formed about the tube or body It. The area of suchconfinementbeing, at least the- 5 area in. which the strip H undergoesstretching and comprasion stresses while being edgewise .bent about thetube or body ll. Adjacent-the surface of tube or body I. and on oppositesides of the flat strip .II is a tangential area i8 in which strip I lis'unconfined on both of its sides, in the area in'which the strip II issubjected to compression stress while being bent about the -tube or bodyII. By this partial confinement and partial freedom'from confinement ofopposite sides of the strip H, in accordance with my invention, I avoidthe lateral deflections of tube or body It, and the consequencesthereof, that have heretofore resulted from the leading of the strip lledgewise towardthetube'orbody ll underthe 5 heretofore requiredsubstantial longitudinal stress. In the Eresent invention; the strip I Imay out permittingthe some to wrinkle, whereas with my inventionsubstantially less power is required insobendingthestrip-ll astopermitacontrolled fl'wrinklingoftheinner edge of strip ii togetherwiththetransformationofthewrinklesinto the' In this smoothing out ofeach wrinkle I! the "10 metal content r each wrinkle I: is smoothed orworked inwardy' toward the exterior. surface of the tube in a planecoincident with the outer periphery of the strip l2 and of a thicknesssubstantiaily corresponding to the thickness of the bent 1s strip 12st"its periphery. The surplu's metal'reing strip to. the tube or body ll.

body I. and the Subsequently each wrinkle If issmoothed out by hand orby any suitable tool.'

sulting from suchsmoothing of each wrinkle II results in the formationof a foot l3 extendin laterally from the inner edge of the bent strip H,and such feet l3 alternate on opposite sides of said 'edge substantiallycoincident with each s smoothed out wrinkle. The wrinkles I! which areprovided and permitted to form on the inner edge of strip If within thearea I, Fig. 6, may be ironed out leaving a flat strip I I unwrinkled atits inner edge and the surplus metal that was in lo the wrinkles beingtransformed into the alternating feet It by the edge of the confiningsurfaces 28 coinciding with the outer edge of the tangential free andunconfined surface I of the strip ll while being bent about the tube orbody II. In 15 such case said coinciding edges would be thecorresponding coincident edges of a metallic member upon opposite sidesof strip H. I

Each" foot 13, or each selected foot i3, is then suitably secured to thetube. One form of such securement as indicated in Figs. 3 and 5 is thatsuch feet are pressed with their inner surfaces a slight distance belowthe normal exterior-surface of the metal of the tube or body II. Thisresults in a multiplicity of different angular-shapedand T positionedportions of feet It being interlocked into slight recesses in theexterior surface of the tube or body HI thereby forming a rigidsecurement of the reinforcing strip to the tube.

The feet I! of Figs. 4 and 8 are similarly formed, a but instead of thewhole or a substantial area of each one, or certain selected ones, ofthe feet II being depressed into metal of the tube or body II asindicated in Figs. 3 and 5, the feet II of Figs. 4 and 8, or selectedones thereof, are secured to the I tube It by,having at least onerelatively slight depression formed therein. In forming each depressionIf some metal of foot is is thrust inward, thereby'forming'in theexterior, surface of tube or body III a relatively slight depression ll,40

registering with depression I! and interlocki s metal of the feet Itwith metal of the tube. This forms a substantial securement of thereinforc- In commencing to form the reinforced pipe or tube inaccordance with my invention an end of a strip ll may be brought intoedgewise contact 7 with a portion of the exterior surface of tube orsame at such point initially soldered or' otherwise secured together.The strip H may thenbebentineitheraringorhelixas may be desired'abouttube or body ll either by hand or'by apparatus. In either hand orapparatus coiling there is relative revolvable motion oftubeorbody ilandtheunbentportionofthe strip n.

The wrinkles I! are shown more clearlyin Figs. 5, 6, '1', and 8. Thelength of wrinkles II in the width oi' bent strip I I may be controlledby confining the desired extent of the (liter edge or"vstripll,atthetimeitisbeingbentorcoiledabout 'thetubeorbodyil. e

r In the 'pparatus ditieally disclosedin Figs. B'through 9, 25represents a tool steel dye plate adapted to be mounted uponthecross-slide of a lathe or like tool between whose centers the tube orbody II is mounted to revolve. The edge 7 of plate I! is provided with asurface" eonforming to the arc of a circle concentricwith the center ofthe tube or body II, and whichsurface merges into a surface 2l tangentto said surface I 2'. Extending into said surfaces 26 and 21 and theadjacent surfaces of the inner end of plate 25 is a groove 2| whichconforms to the thickness and are into which thestrip u istobeu onenessbent and formed. Theta-ngential surface 21 at its highest point extendsonly to a point within -the width of the strip ll, shown in Fig. ,6 thesame extends to a point approximately one-half the width of strip I I.The groove 28 confines the strip ll whilebeingbent so as to maintain thesame free'from while the space between the tangential surface 21 and theouter surface of tube or vltes the formation of wrinkles It in theprogressive bending 'of strip ll edgewise about the tube or body ll. Assuch wrinkles I! are formed in such space progressively with the stripII with the apex of each of said wrinkles I! being at or adjacent thesurface 21 near or at its wider divergence fromthe exterior surface oftube or body I I," the rotation of tube or body II with the edge of theend of strip I l secured thereto and entering the groove 28 in plate 25the strip ll commences to progressively bend about the tube or body Inand the wrinkles l2 to progressively form within the entrance to thespacer represented by the tangential surface TI of plate 25 and theadjacent surface of tube or body it. As the tube or body secured end ofthe strip ll, the'tangential surface 21 of plate 25 progressively uponopposite sides of strip ll smooths out the wrinkles I! by pressureapplied substantially radially inward toward the against which saidsurface 21 deposits the surplus metal from each wrinkle I! in the formof such deposited foot ll. Each of these feet I3 is in the instanceshown in Figs. 3 and 5 pressed inwardly against and below the exteriorsurface of the tube or body Ill forming a slight depression therein.This is accomplished by the emerging surfaces 26 and 21. Such feet |3being so depressed into said depressions 30 at separated points aboutthe arched surface of the tube or body substantial interlocking of theand the tube' or body It in angular relationships to each a rigidsubstantially-permanent securement together of the strip l l and tube orbody ll. In

metal of strip such spaced and such secured position the inner edge ofstrip- II is in firm engagement throughout'its extent with the outersurface of the tube or body II.

While there is required to be no substantial longitudinal stress in thestrip H as the same.

approachesthe tube or body ll there is therefore no lateral thrust uponthe tube or body ll. There is, however, 111121 18 bending of strip llabout the tube or body ll designedly set-up longitudinal stressespecially at the outeredge of the bentstrip I progresses from a pointin the width of the strip ll substantially coincident with that of theapex of each of; the wrinkles 12. This longitudinal stress in the bentstrip ll does not occasion any lateral stress upon the tube or body llbecause such longitudinal stress is occasioned by the, in eflect, radialstretching of the stated outeriedge of 'the strip ll while the sameisbeing formed about 'the tube or body I), and which stress isonlyunldirectional about the tube or body Ill.

1 In smoothing out the wrinkles therefrom the feet II, by tangentialsurface il of plate 25, there results a slight lateral thrust upon thetube or body. by a steady rest bar supportedby the crossslide of theaforementioned lathe or like tool. This bar II is providedwith a surfaceadapted and in the nstance wrinkles,

ody II inbending of interlock as Ill further revolves with its surfaceof tube or body II III affords such a other as to afford H, whichlongitudinal stress progressivelyformed l2 and forming I! which isneutralized to engage the exterior'surface of tube or body I at a pointdiametrically opposite the tangential surface 21 which occasions saidthrust.

Instead of the feet ll being depressed into and forming depressions IIin the exterior surface of the tube or body It the feet with the forinof my invention 4 and 8, are firmly pressed virgin surface of the tubeor body ill. A slight ridge 3! projects from surface lion opposite sidesof the strip ll. Said ridges form slight depressions 33 in the exteriorsurface of each foot l3 and force the adjacent metal of each foot I 3inwardly to cause a corresponding depression 33 in the exterior surfaceof the tube or body Ill. The metai'of each foot I3 between saiddepressions 32 and 33 by the nature of such well as the spaced apart anddifferent angularity of the interlocked metal of each foot with themetal of the tube or body Ill, forms a rigid and practically permanentsecurement of the strip II to the tube or body III.

In Fig. 9 the surfaces 21'are shown to have only partially straightenedout the wrinkle, but it will be readily understood therefrom by thoseskilled in the art that there is suflicient surplus metal of eachwrinkle, left after smoothing out each wrinkle, to form each foot II byscraping this surplus metal inwardly toward the surface of the element;

.While I have indicated but oneform of apparatus by which my inventionmay be'pracii, in accordanceticed, in addition to the disclosure thatthe same invention vby those skilled in the artas well' as more readilyenable such sldlled persons to select,ladapt, and employ differentformsv of other apparatus for the practice of my invention.

It will be understood by those skilled in the art that my inventionconcurrently and progressively wrinkles the inner edge and stretches theouter edge of the strip Ii while being wound edgewise about the tube orbody In; that the wrinkling of the inner edgevery substantially lessensthe power required to bend the strip ll and that a wider, thinner stripll may be employed by my invention than was possible under priorpractices; that the ironing out of the wrinkles l2 into the feet l3coldrworks the inner portion of the width of the edgewise bent strip I Iabout the tube or body ill and increases the rate of conductivity ofheat or cold by way of the inner portion of strip .H to and from thetube or body portion III; that the progressive stretching of theunwrinkled portion of the width of the strip II, while being wound aboutthe tube or body ll, affords such a cold working of such portion ofstrip II as to substantially increase the rate ofconductivityof heat orcold bywayv or said portion of said strip II to and from the tube orbody It, and also retains in certain outer portion of the width of thebent strip li' a longitudinal stress, lesser in degree than required tostretch the metal of strip II, but

exerting a substantialstiifening effect upon said portion of the widthof strip II as to maintain the stability of the formed strip II andincrease its resistance accidental lateral bending or was heretoforepossible with thicker strips of metal; that-the thinness of the wall ofthe tube :10 deformation by thinner metal of strip ll than withoutdeparting from "ofagivencapacity decreases the cost of production of mynew and useful heat or cold exchanging element as well as my greatlyincreases its lightness; rate of heat or cold exchangin capacity anddurability; and that'the product and process portions of my unitary.related 'and independent invention posauses other inherent advantageswhich may be The substantial lesser weight of metal required in theconstruction of my present invention;

the strength and dura- Hllty of the resulting product, together with theincreased eillciency of the resulting product in the increased rate atwhich it my exchange heat or cold, mch involve substantial savings inthe money costof the material, in the size and weight of and spacerequired'for each unit afford great savings not only in-the production,but also in the use of the resulting product portion of my-invention. Itwill be further likewise understood that even small savings in theproduction and use of each foot. in length of each of the elements, Fig.1, of my invention are multipliable by the number of feet requiredand/or the number of days in eachyear in which the same is used, and.that the rash: will be a more comprehensive indication of theadvancement in the art achieved by this invention. Y

This invention may be made and used by or for the Government of theUnited States of America for governmental purposes without the paymentof any royalty thereon or therefor.

Having now so fully described my invention that others skilled in theart may-therefrom make and use the panic. to secure by Letters Patentis:

1. In. apparatus for makings reinforced tube having a rib extendingflcompriain adie'havlngarecessinoneedge thueof metal. and-said dieadaptedtoreceiveaportionofthetube,saiddieedgehavingaslotthereinadaptedto receive and laterally support therib forming havingaprogressively de-' creasingrdepth offlateralsupporting slot to mothout'thewrinkleontheinneredgeofthe which comprisesthe of said member by what I claim and desire- 1 adaptedto receive andlaterally support the rib edgewise there-about.

rib forming metal and to displace some of the metal of the wrinkletowardand into binding contact with the metal of the reinforced tube.

2. The process of making a reinforced member steps of bending a metalstrip edgewise on the said member and conforming one edge thereof saidmember by wrinkling said strip at least at said conformed'edge, andsmoothing out the wrinkles to form laterally projecting feet at theconformed edge of said strip.

ing one edge thereof to the desired surface of said member by wrinklingsaid strip at least at said conformed edge, and smoothing out thewrinkles by pressing the metal of the wrinkled portion of the striptoward the said member to form laterally projecting feet atthe conformededge of said strip. v 4. The process of making a reinforced member whichcomprises the steps of bending a metal strip edgewise on thersaid memberand conforming one edge thereof to the desired surface wrinkling saidstrip at least at said conformed edge, smoothing out the wrinkles bypressing the metal of the wrinkled portion of the strip toward the saidmember to form laterally projecting feet at the-conformed edge of saidstrip. and pressing at least alportion of some of said feet into theexterior surface of said member." a

'5. An apparatus for making a reinforced body having a rib extendingedgewise thcreabout, comprising a die having a slot'in an edge thereofforming metaL'the said slot having a varying depth which is least atthat end where the rib forming metal is initially and the slotted beingprovided with a surface for pressing the rib forming metal in adirection outwardly of said slot and into intimate contactwiththebodytoberibbed.

